This invention relates to apparatus for producing and dispensing frozen confections by depositing a liquid mix onto a freezing surface as a thin layer and then scraping the resulting frozen product from that surface into a container. It relates especially to an improved non-stick freezing surface for such apparatus.
1. Field of the Invention
Frozen food products such as ice cream and frozen yogurt are now being produced by depositing a flavored liquid mix onto a freezing surface so that the liquid mix spreads out on that surface as a thin layer which is immediately frozen or partially frozen. The product layer is then scraped from the freezing surface into a container, or more preferably, into a compaction device which compacts the frozen scrapings into a solid body or xe2x80x9cscoopxe2x80x9d which is thereupon deposited into a container such as a cup or cone. An example of an apparatus for producing a frozen food product in this fashion manually is described in U.S. Pat. No. 5,473,909 and related patents. Apparatus for producing and dispensing such products automatically using a rotating freezing surface is described in application Ser. No. 10/160,674, filed Jul. 31, 2002, the contents of which is hereby incorporated herein by reference. It should be understood, however, that the invention has application to other surfaces which may come into contact with frozen ice cream, yogurt and the like products, e.g. continuous or batch freezers.
2. Description of the Prior Art
Conventionally, the freezing surfaces with which we are concerned have consisted of the finished surfaces of thermally conductive platens or tables through which a refrigerant is circulated in order to cool the freezing surfaces to a low temperature, e.g. xe2x88x9215xc2x0 F. to +5xc2x0 F. In prior apparatus of this general type, it has been the practice to provide the platen with a mirror smooth surface which is devoid of any coating. This is because in the frozen food industry it has been the prevailing view that such coatings provide sites for bacterial growth when contacted by a food product for an appreciable period of time. In fact, the National Sterilization Foundation (NSF) has promulgated rules prohibiting the use of non-stick or other coatings on freezing surfaces contacted by ice cream and other frozen confections. Resultantly, product tends to adhere to freezing surfaces of the type described in the above patent/application. This can be troublesome when dispensing ice cream or frozen yogurt having different flavors because of product carry over from one serving to the next.
It would be desirable, therefore, if the apparatus described in the above-identified patent/application could be provided with a non-stick freezing surface in order to facilitate complete removal of the frozen product from the freezing surface between servings.
Accordingly, it is an object of the present invention to provide an improved freezing surface for apparatus that produces and dispenses frozen confections.
Another object of the invention is to provide a platen or table having a non-stick freezing surface for easy wear of the confection.
Yet another object of the invention is to provide a non-stick surface for quickly freezing a liquid product mix deposited as a relatively thin layer on that surface.
Other objects will, in part, be obvious and will, in part, appear hereinafter.
This invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the following detailed description, and the scope of the invention will be indicated in the claims.
Briefly, the non-stick freezing surface herein is constituted by the upper surface of a thermally-conductive platen. The surface has a smooth finish and is coated with and organic metal polytetraflouroethylene (PTFE) material.
The freezing surface retains its non-stick characteristic when cycled repeatedly between temperatures in the range of xe2x88x9215xc2x0 F. and room temperature (70xc2x0 F.) over a prolonged period.